Conical antiferromagnetic order in the ferroelectric phase of Mn0.8Co0.2WO4 resulting from the competition between collinear and cycloidal structures
Urcelay Olabarria, Irene (Institut Laue-Langevin)
Ressouche, Eric (Commissariat à l'Énergie Atomique et aux Énergies Alternatives (França))
Mukhin, A. A. (Institut obshcheĭ fiziki im. A.M. Prokhorova)
Ivanov, Vsevolod (Institut obshcheĭ fiziki im. A.M. Prokhorova)
Balbashov, A. M. (Moscow Power Engineering Institute)
García-Muñoz, José Luis (Institut de Ciència de Materials de Barcelona)
Skumryev, Vassil (Universitat Autònoma de Barcelona. Departament de Física)

Fecha:	2012
Resumen:	Evolution of competing commensurate collinear (AF4) and incommensurate cycloidal (AF2) magnetic structures in Mn0. 8Co0. 2WO4 multiferroic was studied by neutron diffraction, magnetic, and pyroelectric characterization measurements. In contrast to pure and slightly Co doped MnWO4, the antiferromagnetic AF4 collinear phase [k1=(1/2,0,0)] inherent to the pure CoWO4 was observed below Néel temperature TN≈20 K in Mn0. 8Co0. 2WO4. This collinear order survives down to the lowest temperature reached in the experiments (2 K) even after the appearance of the second (cycloidal AF2) spin order below TFE≈8. 5 K [k2=(−0. 211,1/2,0. 452)]. Ferroelectric polarization along b axis was revealed below TFE in the low temperature conical phase resulting from the superposition of the AF4 and AF2 spin structures. The arrangement of the spins after the two successive magnetic transitions are thoroughly described. In particular, we found that spins in the AF4 phase are aligned along the easy direction in the ac plane (∼142∘ with respect to the c* axis), while the cycloidal AF2 spin order is developed in the magnetically hard directions, perpendicular to the easy one, and consequently the TFE decreases compared to the pure MnWO4.
Ayudas:	Ministerio de Ciencia e Innovación MAT2010-20616-C02-02 Ministerio de Ciencia e Innovación MATT2009-09308 Ministerio de Ciencia e Innovación CSD2007-00041
Derechos:	Tots els drets reservats.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió publicada
Materia:	Física de l'estat sòlid ; Magnetisme ; Superconductivitat
Publicado en:	Physical review B : condensed matter and materials physics, Vol. 85, Núm. 22 (June 2012) , p. 224419/1-224419/6, ISSN 1098-0121

DOI: 10.1103/PhysRevB.85.224419

6 p, 880.4 KB

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Documentos de investigación > Documentos de los grupos de investigación de la UAB > Centros y grupos de investigación (producción científica) > Ciencias > Grupo de nanoingeniería de materiales, nanomagnetismo y nanomecánica (Gnm3)
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